Collet



Oct. 20, 1931. M. .1. MATTHEWS 1,327,795

COLLET I Filed March l2 950 ZSheets-Sheet l INVENTQR Mal for! f/Waiihewa.

ATTORNEYS.

Oct 20, 1931. M. J. MATTHEWS 1,827,795

COLLET Filed March 12 930 2 Sheets-Sheet 2 II I' I ii I1 34% I I 1 I l II I my INVENTOR ML' Z Zorz fMdi-ihcws.

lwwwy ATTORNEYS.

Patented a. 20, '1931 UN T D] STA S I MILTON. J. 1VIATTHEWS, OF DETROIT, MICHIGAN I v corner I Application fiIedM-arch 12,1930. s mu No. 435,147, I

This invention relates to collets. I s e The main objects ,of this invention are to provide an improved form of, collet WhlCh will securely grip material placed therein;

5'to provide a collet in which jaws are movable in such a manner as to compensate for variations in the materialstock placed therein; to provide an improved, form of collet in which the inner faces of the gripping jaws are maintained in parallel relation to each other and to the exterior surfaces of the stock a collet which. will with equal efficiency grip a wide rangeofdiameters of stock material.

An illustrative embodiment ofthis invention is shown in the accompanyingdrawings,

in which: V

Fig. 1 is afragmentary longitudinal sectional view of my improved collet mounted ,inaspindle.*"i" Fig. 2 isan enlarged view in longitudinal elevation of my improved'construction of collet. p j

Fig. 3 is a front end view ofthe same; i Fig. 4 is a sectional view taken on the line 4-4 of Fig.2, looking in the direc'tionindicated by the-arrows. r

Fig. 5 is a sectional view taken on theeline 5-5 of Fig. 3, looking in the directioneindicated by the arrows. V

fied form'of collet with a portion thereof broken away to show the interior construction. j 4 Fig. 7' is a front end View of the same. i

'ithas been customary to take a piece of tubular material and cut axially extending slots, usually at right anglesto'ieach'other, with the intersection atthe longitudinal axis of the device, said slots exte'nding inwardly from one end of the collet.

This construction provides four portions of equalslze, integrally extendingax ially from the baseshank. Theouter endsof these 1 portions are beveled so that when either the bar of stock material placed therein.

Fig. 6 is a view in side elevation of a modi- Heretofore in the construction of collets, J I u *struction, this'objection has been overcome drawn into a spindle or pushed outwardly in the. spindle, depending upon the direction of the bevel, the/split tongue portions of thcolletare sprung inwardly to grip By reason of these portions, which are usu= ally termed jaws, being integrally formed on thebase shank. they swing through the are 7 of a circle, the radius of which is substantially the depth of the slots cut in the colleteo With this kind of a movement it is obvious that there can be only one point at which the gripping faces of all four jaws will be parallel to each other, and parallel to the.

outer'surface of the stock material placed therein. Any variation of size in the stock material from this one exact point will cause 'theinner faces of the collet jaws to become out ofparallel with'e'ach-other, so that the entire face will notevenly and uniformly I grip the surface of the stock material placed therein. With suchtype of collet it is necessary to exert great pressure on the collet in order that it will grip the bar of, stock ma terial with suficient security. With my improved construction of collet the gripping jaws are mounted so as to have true radialmovement bodily with the gripping faces of the jaws maintained in parallel at all times, so that the entire face of the jaw will, evenly and'uniformlygripthe bar ofs'tojck material. I e

Another difficulty vwhich has been experienced with prior art collets has been where the bar of stock material isslightly out of vround. In such instances two jaws only of the collet willgrip the barof stock material and the othertwo will'notexert any appreciablegripping action on the stock.

In the preferred form of my improved con lts. cross-section is the greatest will slightly 'recede fromthe beveled end of the spindle and the two opposite jaws willslightlyad Vance. The arrangement" is such thatlthe' movementis' equalized, and all four jawswill contact with the beveledfend offlthespindle with equal resistance and will grip the bar of stock material with equal pressure.

In the construction. shown in the drawings, a tubular shank member 8 is provided with a portion 9 of reduced diameter at one end thereof, thus providing a shoulder 10 at the point where the diameters change. The shank 8 at diametrically opposite sides and adjacent to the shoulder 10 is provided with substantially annular sockets 11 and'12'in which are pivoted trunnions 13 andl t respectively, of a pair of semi-circular intermediate members or sleeves 15 and 16 respec=- tively.

The sleeves 15 and 16 loosely surround 01 embracethe reduced portion 9 of the'shank membergand the edges thereof adjacent to the shoulder lOare cut away as shown at17 and18, soas to provide clearance with respect to the shoulder 10, and thus permit rocking of the members on the pivoted trunnions,

which trunnions are positioned substantially medially of their respective members.

Each of the intermediate members 15 and 1 6 is provided with axially extending. substantially annular trunnions 19 and 20, the side walls of which extend radially with respect to the longitudinal axis of the shank 8. J aw members 21 and 22 are'provided with complementarysockets 23 and 24 respectively for fitting upon the trunnions 19 and 20, thus providing interfitting connections which permit radial slidingmovement of the jaws 20 and 21. The end of the intermediate'member 15 adjacent thejaws 21 and 22-is also cut away as shown at 25 to'provide clearance-so that the jaws have limited rocking'action on their trunnions as well as radial sliding movement.

A similar'pair of jaw members 28 and 29 are mounted in the same manner upon the intermediate member 16, so that the four ,jaws complete the device, two being-mounted on each of the intermediate members.

The axis of the .arcuate socket and trunion, as clearly evidentfrom Fig. 3, substantially coincides with a radius of the shank member, and hence of the jaws." The limited rocking movement of the jaws on their trun- "nions, then occurs respectively, in planes substantially perpendicular to each radii. Hence the jaws can move radially toward the axis of the shank member and j aws, and 7 turn in planes respectively perpendicularto' such radii, thereby permitting accurate adjustment of the jaws with respect to a work piece between them.

Means are provided" for normally urging the jaws outwardly in a radial direction, and

comprise a split ring 26 of spring material mounted 1n a circumferentially extending Q groove 27 formed in the inner faces of the jaw members.

7 it In the modified form'of construction shown in Figs.6 and 7dofthedrawings, altubular shank member 30 is provided with four trun-' nions 31, equidistantly spaced therearound,

the side walls of which extend radially with respect to the longitudinal axis of the shank. Four jaw members 32, all of the same construction, are mountedupon the trunnions 31 so as tobe radially movable with the jaw faces 33 in parallel relationship at all times. A split ring of spring material 34 is provided in a circumferentially extending groove 35 for normally urging the jaws outwardly so as to receive a bar of stock material therein. In the operation of this collet it is placed in a spindle 36 and when moved outwardly relatively to the spindle, the outer sloping faces 37 oft-he jaw members contactwith the complementary beveled face. 38 ofthe spin dle, thus camming the jaw members inward- 1y to grip the bar of stock material placed therein. The jaw members slide on their respective trunnion so that the gripping faces.

.39 are maintained in parallel relation at all times. j j r If the bar of stockmaterial is slightly out of round so that its cross-sectional measurement at one'diameter is greater'than at an other, the two opposite jaw members which engage thelarge part of the bar will recede inwardly by reason ofthe rocking action of the intermediate members 15 and 16. The rocking of these intermediatemembers will carry the opposite jaw mounted on each intermediate member outwardly, so that all four jaws will contact with the same pressure against "the beveled faceoii' the spindle. In

this manner, all four j aws'will be'forced inwardly to grip the bar of stock material with the same pressure, this pressure being equalstood that numerousdetails of the constructions shown may be altered or omittedwithout departing from the spirit of this invention, as defined bythe following claims. I claim: l

1. An equalizing collet comprising a shank member, intermediate members rockably mounted on said shank member and a. plurality of jaw members radially. slidable'on said intermediate members. 1

'2. An equalizing'collet comprising a shank member, intermediate members rockably mounted on said shank member, aplurality of -jaw members and radially extending, in- 1 ter-fitt1ng portions on said intermediate and lar shank member having a portion of less shank member,

a pair of jaw members radially-slidableon each of said intermediate members.

4:. An equalizing collet comprising a shank member, a pair of mtermediate members rockably mounted onsaid shank member,'a pair of jaw members radially slidable on each of said intermediate members, and means for urging said jaws outwardly.

5. An equalizing collet comprising a shank member, intermediate members rockably mounted on said shank member, a plurality of jaw-members radially slidable on said intermediate members,said jaws having a circumferentially extending groove in their inner faces and a-ring of spring material in said groove for urgingw said jaws outwardly.

6. An equalizing collet comprising a tubuoutside diameter on one end thereof, a pair of semi-circular intermediate members rockably mounted at their medial points on said shank member, said intermediate members surrounding said smaller portion inrloosefitting relationship, and a plurality ofjaw members radially slidable on said intermediatemembers.

7. An equalizing collet comprising a tubular shank member having a portion of less outside diameter on one end thereof, apair of semi-circular ntermedlate members rockably mounted at their medial points on said-- toward the longitudinalcenter line of'the aws,.the aw members being rookable'about shank member, said intermediate members surroundlng said smallervport on lll'lQOSG- fitting relationship, a plurality of jaw mem} bers and radially extending, inter-fitting portions on said intermediate and jaw members for slidably supporting said jaw members.

8. An equalizing collet vcomprising a tubular shank member having a portion of less outside diameter on one end thereof, a pair of semi-circular intermediate members rockably mounted at 7 said intermediate members surrounding said smaller portion in loosefitting relationship, a plurality of jaw members, radially extending, inter-fitting portions on said intermediate and jaw members for slidably supporting said jaw members, said jaws having a circumferentially extending groove in their inner facesand a ring of spring material in said groove for urging said jaws outwardly,

9. An equalizing collet comprising atubu lar shank member, a pair of circumferentially extending. intermediate members" rockably mounted at their medial points on the shank member and having substantiallyradial axes of rocking movement, and a plurality of jaw.

members'rockably mounted on theintermedi ate members.

- in imted?ak h i their medial points on said,

410-; elii ra ascol et n i n a t-I lar shank membenjapairof circumferentially extending;intermediateI members frockably i p'eintslent e sh k member having substantially radial l axes ofi lqk i g 1 93 ent p lity of l memberszro 'kably mountedon the intermedi} at mem e sand av sut aaiel sea axes of rtickingmovement.,, a, a a .1 1. .,A nequalizing collet comprising-a tubuf lar sha'nk member, a pair of circumferentially extending intermediate .;memberj s rockably mounted at substantially; their, medial points tiallyl radial axesv of rocking movement," and a .pluralityof jaw members rockably mounted and having sub; 7

12. Anequalizing colletcomprising a tiibu lar shankmember, a pair of circumferential ly extending intermediate members rockably mounted at substantially their medial points on the shank member and having substantifrolnthds'hank member and having substailally radial axes of rocking movement, and a plurality of jaw members relatively mounted f on the intermediate members, each intermediate member rockably supportinga pair of the 'jawmembers. I i Y 13. A collet comprising a vice, V and a plurality: of circumferentially spaced jaw members at one end "of the supr porting device, each-ofthe jaw members and 5 P r" ,ro-o the supportin'g device having interfitting,

supporting dea l arcuatesurfaces, the axis of which extends"".'

such axes. a a v 14. A collet comprising a supporting de vice, and a plurality of circumferentially f spaced aw members at one end of the supporting device, each-of the jaw members and the supporting device having interfitting ar cuate surfaces, the axis of which extends toward the longitudinal'center line of the jaws,

the jaw members being rockable about such 7' axes, and slidable along the arcuate surfaces of the supporting device toward or away from v said center line. r

15.- A collet'comprising a supporting device, a plurality of circumferentially spaced jaw members at one end of the supporting device, and means connecting each jaw mem-' ber to the supporting devlce, said connection Y including an arcuate socket formed in one of the connected parts, the axis of whichex- 7 tends toward the axis of the jaw members,

and a trunnion on the other part which is the "connectedparts, the axis of whic'hextends V toward the axis'ofjthe jaw members and a V trunnion on theother part'which' is disposed device, and means cofihecting eah jaw me'm berto the supportlng dQ V ICG, sa ld connectlon incluclmg anarcuatesocket formedm one'of in said socket;and which .is slidable insaid socket toward the 'aXis' of the jaws; 'whereby the jaw members have rofc'king move'ment about the axes v ment alongsaidaxes."

vice; a plui ality ofjaw'members arranged in "17'." A collet comprising a si pporting deoircu'mferentially spaced relation at one end of the suppoyt'ing device, and means connect- Q mg each aw member to the supporting dBVlCG: forrockm'g movement about an axls substantially perpendioularto and substantially in- 'tersecting the axis of the jaw members, and sliding movement along the firstax'is; 1 MILTON J. MATTHEW/VS.

of the socket andsl itling-move- I 

